MicroRNA-34a 对小鼠气道平滑肌细胞增殖和ORMDL3 表达的影响

目的 探讨支气管哮喘小鼠模型中microRNA-34a（miR-34a）对气道平滑肌细胞（ASMC）增殖与血清类黏蛋白1 样蛋白3（ORMDL3）表达的影响。方法 以卵清蛋白（OVA）诱导复制的小鼠哮喘模型和培养的ASMC 为研究对象，筛选与ORMDL3 密切相关的miRNA ；利用miR-34a-mimic 使miR-34a 过表达；用苏木精- 伊红染色和MTT 法探究其对ASMC 增殖的影响；实时荧光定量聚合酶链反应和Western blot 检测ORMDL3 的表达变化。结果 OVA 诱导下小鼠气道组织中miR-34a 被抑制（P <0.05）。miR-34a-mimic 可减少哮喘小鼠ASMC 异常增殖（P <0.05）；miR-34a-mimic 抑制ASMC 在490nm 下的光密度值和相对细胞活性（P <0.05）；miR-34a-mimic 下调哮喘小鼠气道组织中ORMDL3 的表达，并抑制体外培养ASMC 中ORMDL3 的表达（P <0.05）。结论 miR-34a 可抑制ASMC 的增殖和ORMDL 3 基因表达，为今后哮喘发病机制的研究提供新的思路。

MicroRNA-34a inhibits proliferation of airway smooth muscle cells and expression of ORMDL3

Objective To explore the regulating effect of microRNA-34a (miR-34a) on airway smoothmuscle cell (ASMC) proliferation and orosomucoid1-like protein 3 (ORMDL3) level in bronchial asthma modelof mice. Methods The mouse asthma model was induced by ovalbumin (OVA). ASMCs were cultrued in vitro .MicroRNAs which were implicated with ORMDL3 were screened. miR-34a was overexpressed by miR-34a-mimic.Hematoxylin-eosin (HE) staining and MTT method were used for the detection of ASMC proliferation. Quantitativereal-time PCR and Western blot were used for examining the expressions of ORMDL3. Results The level of miR-34a was markedly inhibited in the airway tissues of the OVA-induced mouse model (P < 0.05). The abnormalporliferation of the ASMCs was attenuated by miR-34a-mimic (P < 0.05). The OD value at 490 nm and the relativecell activity of the ASMCs were significantly downregulated by miR-34a-mimic (P < 0.05). The expression ofORMDL3 in the airway tissues of the asthma mice was significantly inhibited by miR-34a-mimic (P < 0.05). In vitro ,miR-34a-mimic also downregulated the ORMDL3 level in the ASMCs (P < 0.05). Conclusions miR-34a plays arole in inhibiting the proliferation of ASMCs and regulating the expression of ORMDL3, and it can provide new ideasfor understanding the pathogenesis of asthma.